1. Field of the Invention
The present invention relates to a fabrication method of blue light emitting ZnO thin film phosphor. More particularly, the invention relates to a fabrication method of blue light emitting ZnO thin film phosphor simply by heat treatment without making Al-added alloy.
2. Description of the Related Art
Previously research on the phosphor over visible light range has been performed for compound semiconductors such as ZnS, ZnSe, ZnO, and so forth. However, due to the native defects of nonstoichiometry of this research, the emission characteristic has been limited to red and green series.
Meanwhile, the blue light emitting phosphors have emerged recently to be important for accomplishing full color representation in the flat panel display (FPD) field.
Among these blue light-emitting phosphors, ZnO has known to be green light emitting by interstitial Zn and O vacancy.
Up to the present, ZnS:Ag and Zn gallate (ZnGa2O4) have generally been used as major blue phosphors.
For the case of phosphors using ZnO, alloy-type powder such as ZnGa2O4 or thin film type phosphor has been developed.
For the case of blue light emitting phosphors using ZnO besides ZnGa2O4, cathode luminescence of Ta2Zn3O8 and ZnWO4, which has luminescence peaks at 410xcx9c417 nm and 490 nm, respectively, has been developed by making alloys of Ta and W. [Refer to University/Government/Industry Microelectronics Symposium, 1997, Proceedings of Twelfth Biennial, IEEE, P. 161 and Mat. Res. Soc. Symp. Proc., v. 560, 89 (1999)]
It is an object of the present invention to provide blue light emitting ZnO thin film phosphor by vapor-depositing through sputtering and heat-treating slightly doped targets without the conventional alloying process in which the phosphors using ZnO form spinel structure as in WO3, Ta2O5, and Ga2O3.
To achieve the aforementioned object, the present invention is characterized by loading a substrate that is vapor-deposited with dopant-added ZnO thin film into a heat-treating chamber, and heat-treating it quickly under gas atmosphere to activate the dopant.
The above and other features and advantages of the present invention will be more clearly understood for those skilled in the art from the following detailed description taken in conjunction with the accompanying drawings, which form parts of this disclosure.